In order to improve the bandwidth of the conventional sub-harmonic mixer, a broad-band, high intermediate frequency(IF)sub-harmonic mixer for W-band applications is proposed. Replacing the open and short stubs that are used in the convertional sub-harmonic mixer with a broad-band band-pass filter and a low-pass filter, respectively, a wide operating frequency band is achieved. Furthermore, without the use of the edge-coupled band-pass filter at radio frequency(RF)port, the proposed structure can be realized by common hybrid microwave integrated circuit technology at W-band. The measured results show that the proposed sub-harmonic mixer can operate from 80 to 107.5 GHz for RF frequency and support up to 18 GHz for the IF bandwidth. Also, the measured results show that the single-sideband conversion loss is less than 13.7 dB over the available RF frequency band, while the minimum conversion loss is about 9 dB at an RF of 92.5 GHz and an IF of 3 GHz. Thus, a large operating bandwidth performance at W-band can be achieved by the proposed mixer.